check mysql version

mysql --version

Default value of bind-address shows below:

Default Value (>= 5.6.6) *
Default Value (<= 5.6.5) 0.0.0.0
So actually don't need set bind-address for above mysql version.

check mysql config file location

$ which mysqld
 /usr/local/mysql/bin/mysqld
 $ /usr/local/mysql/bin/mysqld --verbose --help | grep -A 1 "Default options"
 Default options are read from the following files in the given order:
/etc/my.cnf /etc/mysql/my.cnf /usr/local/mysql/etc/my.cnf ~/.my.cnf

check is there any bind-address config in above config files.

restart mysqld service

service mysqld restart

confirm mysql user created with user@'%' to allow user connect mysql outside.